Automatic empty and load brake equipment



Oct. 26, 1943. J. WHITE- AUTOMATIC EMPTY AND LOAD BRAKE EQUIPMENT Filed :Iuly 22, 1941 v0 :0 on Y m 5 W 1 m9 5 mo I mm T Q r I! NW :v m an m 3 Y EVE V M O@ @N ON NW INVENTOR JOSEPH WHITE Patented Oct. 26, 1943 v I t jzsszsaoijf V t AUTOMATICzEMPTY AND-:LQAD BRAKE '1 Joseph White, Qoheord, negrlSydnQyfNw South w 7 Wales, Australia, assigno'r -to- '1-he-*Westipgh;ouse Air Brake compan Wilmerding;Pau-acorpo- 1 rationoftPennsylygmia, Application Jo ly .22, 1911 Sj eri aiEST L:411 519 7 l, 2 j lnvm st f lia'Novemberzbjhlflrlfl f loxolaims. (01. 303 23) l This mye io oela e ome n o t a y nsth roos fiohfihatAfazifisentit iean-msiti nt ithe 'yeh c r nrin s anr h here rc th g s .lqas

,birakin r a li d t m ty-a o ded Frai Wa v hic es att nd ng to t w g p ri by the Mehiole. 7

Inthe empty QndJoadmrake systemsgxthereih a separate brakeoylirlder is'provided for use y'vith .m ty an wi h ade eh s h brak n force for the empty ,v ehie1e,is' obtained f rom a bra sie k own s he em ty rak qyl- .in e y nd th -braking or f d a o d d hi e=-i ,pbt ned a im kths emp ra -exhale an -an addit on .v .cy nde zk owma t lqad b r ake c l inde lj,

T egn m pa mwesfii th fln e i 1 201 9 .vide m a s wh e zth v oad.b k c i flerio of th e yehiole.

t e ab y t e Q mPW nd load Dwk mem "i .copt l dk-m rd n t t loa car my h weh cle act o o such a swan he .sp ing the 1 1 9 in seon un t entw th th elat 1 95 130 3 .Q flJ D F lQ PQI'QiQ Q .Qfzt vehicle wi hi e fiqnto anallns un t n 2 Ifhis o'bJ'eet -is attained by the use of an a 0- .mat t a dl a rQ v ce-wh his c nstrukted a d a n o automat cal a u it el z Q e' lq'efiq and advantage vWil ala sar thI Q lo n more d taile .d scription .Q the intention. T j w H e acgompanxin dn w Qe nwingkfi um i kadq as iamma a ifl w; of an empt and 1.9% rake (e uipment.remhodmrsnth inventio a liq tti n th load -,hrak 5 ro ling m an ble rsi n r h pr n zs fleflestiono th ve icle d rin ab ake p l cat o end-war a ns,- ly the maximuni pressure which can, estabr lishedjn the logo. brake cy1ind .er. "The golevieeahas a xt rna leve ndii a a hed to .a portion o -ve iplczthat wanes in N rtic ,reIatiQnShiP with another portion qfgthe .vhicle (,withWhich the fi id ev v t 'd tice can qon aw amoroins to the defleqt qno he pr n there wh c .Q c urseii heve cle- W an pnder the i n fl l erl ce of pressure suppliedirogn h b k equi men is adapte z t o e onl Small dis a vbe re :it buts, on th ortio vq the veh q ew th w h itis ass ciat d W t the loaded r th glesb wwe th added .d fle tipnof th sp n 9f the V hi l perm t k wi)??? move a. greater glista qe before it abuts o the po t o th v isl :conc n di fh :QEVJQE i mtion fiqrn ppq li nth ai pressur e abl shed i ith lpadc inde acco d n i ch-the vehicle spring deflection and the gorl segge nt m vemen o i he l lce pr or o a to ,theflgmss wei ht of b fi p a on. 5 t ans rre 2 2 t eve of z {lo m k c linde s nt llin d ice ut c rd n to th t on scilla ion e bsor d l 'ithfi o' r- Q? W .0 as p and PM d sh pot pisto $119 7 a a ne that A o 231 99691 6 s r c WWI m ty vehicl ldevic .l y

.q lille ypre m bs ni ncre s d to a tszh sen p essu e 5 f inst nc fifte n p unds e p es u e has een inv v fiwcti ats fi iu ua eope at vely ,gon fbt d J stkr sa ers u 0 and 1| .as oqiat d make was to a pl the brake t t m Jij Whe ls a rd' u ti h ilqad m ke sylins er" w 91, 9 13' has ,be n @dius'tje to .its pnqperipost th eqt pn l fivhmkelem 1 whic risiu -umed i ntrmeq at i flencl fw a.. .e .a&i.v o th veh l and i ctred 1t L f i dem rits nq e tran i yahelmehae ng he ie t j draw 7' the? "brake r guin provided with a piston 3a having at one side achamber, 3b in constant open communication with the atmosphere and containing a spring i3c which at all times exerts an upwardly directed-- force on-the piston. At the other side of the piston is a chamber 311 which is iii-constant open communication with the usual triple valvesupply and release passage 36 and which is also in constant open communication withthe -empty. brake cylinder pipe 8. Containedin the chamber 3d, and operatively connected to the piston 3a,

is a valve 3) which is normally maintained seated by the action of the spring 30 through the medium of thepiston 3a to close a communication between the chamber S'dan'd a chamber 39 which is constantly open to the pipe 9, the valve of the spring being such that it will require a fluid pressureof' around fifteen pounds in chamber 3d to cause the piston 3a to move' downjwardly and unseat the valve 3];' Connecting the chamhere 39 and passage 3e is a by-pass communication extending around'the valve 3], 3h in which communication thereis interposed a checkivalve which prevents flow of fluid from the passage 3e to chamber 3g for pu rposes which will hereinafter more fully: appear.

f' Ihe load'brake controlling' device 7' may be carried by either a sprung or'unsprung part of theVehicIaJbut for illustrative purposes is shown mounted on a spring supported part of the vehiclepsuchifor instance as the load carrying body and i nay comprise a casing in which there is ope ratively mounted a control piston having at oneside'a chamber 21 which is in'constant opencom'munication'with the pipe 9 by' -way'of anair strainer 22, and having at the other Side a chamber 23 which is in constant'open-com' munication' with the atmosphere through" a breather passage 24 having an air strainer-25 interposed therein; j

' Contained in chamber 23 is a movable plunger 26 which, at one end, rest on a relatively" light spring 2'! seated: in a suitabl retaining socket provided in the casing. Theother end 'of the plunger is slidably guided within an annularflange 2 8'carried by "thepiston 20,the fl'a"nge being 'long enough'fto provide for a limited rela tive'movement between the plunger andpiston. Interposed between and operatively engaging the piston 20 and a spring seat 29 carried *by the plunger, is a spring; 30 through the medium of which spring the-piston may actuate theplunger. Also contained in the 'chamber;23 is a lever 3| which is secured, intermediate its ends, to'a shaft 32 which is rockably'mounted in the casing. One end of this lever is pivotally connected the flange to the other at,. a. .rate f ast enough ;to permit slow ffree niovernentfofi the member either upwardly or downwardly under normal -operating conditions, which rate, however, will not permit the member to move in either direcltio'n at a'n'abnormally fast rate.

-.L=The oil recess 36 and the chamber 23 are closed w e -ewe e ec io of the casing and has its inner edgejclamped between two sections of the hollow member 34, the diaphragm being pro- :videdtopreventthe lossof oil from the recess 36. "Theiupper end portion of the member 34 is. slidablyi'guided in the casing and engages the" lower side of an exhaust valve seat member}! clamped to the" central "portion of 'thje flexible ph a m w ch sl lezered n 'nla itby wp Sections of the casing. Thevalve-seat539*ispro} vided with a central exhaust passagej'4 ijwhich, t lower c s ers w h a e han ms,- sag'e 42 providedin theupper endof themember 34, which passageg42' is constantly in ope e mL munication with the, atmospheric chamber 23;"

At the upper-side of thefdiaphragnrfflrisfa chamber 43 which isinfconstantopen common; cation with the load brake-cylinder viceF'Gflb'y way of a passage 44, astrainer'45a' 7 Located directly above the exhaust ,v'alvesat 39 and contained in a chamber-J'Iwhichis in constant open} communication with the ma;- phragm chamber *byway' of pass ge and the branch passage 48, is an exhaustvalve 49 which, in its exhaust position, 'as'showm-jrest b annular stop shoulder 5 0-carried bythe casing.

The lower face "of *theexliaus't valve 49 is 'exposed to the chamber 43 and; as'will be 'iater'de scribed,"is adapted tobeengaged by the valve seat 39 to out 01f communication from th'e passag'e '40 and thereby theload "brake cylinder device 6 to the atmospheric chamber 23-b'y way ot'anopem.

ing 5 I- in the member 34 during a load .a'ppli'ca tiono'ithe brake. w I Q One end of the lever 3! has already been described as being operatively connected tofthe plungerZfi for thepurpo'seof controllingithe operation of the lever3i. 'Tfl'le other 'end of the lever extends through the Opening -EI in the ine'mber' and the spring seat '54 a' slight clearance is pripf vide'd for the-purpose of-permitting -a certain to the plunger 23. This lever,fas'will hereinafter appear, is Operative by the plunger torockythe shaft 32L One end of. the shaft extends to.the exterior of thecasing and has rigidly secured theretolan arm '33 which is adapted to 'engagea fixed'or unsprung part I00 of the vehicle.

Slidably mounted in" the casing for movement in thedirection'oppositejto the direction of movement of the plunger 26, is' a' hollow member 34 which, at its lower end is provided with a circular flange 'orIdash-pot piston 35 which'is'slidably guided bythe inner surface of the wall of limited movement' of the -arm 33 -w ithout"thp spring exerting an 'upwardfforce on the member 34.- This'lost motion action-offthe spring;as will hereinafter more fully appear is useful on'l Seated on the exhaust valve 49 and extending upwardlytherefrom' is a tubula'r strut' member 56 within which there is "disposed alight spring 51 which spring at its lower"-end','-restsTon the exhaust valve and at 'its-iippenend'i engages a supply valve'58 contained in a chamber 53' which is connected throughfa p ssage-sag 'toflftheypistqn chamberll. Thissupplyvalve i's' adapted-to ena pipe 48.

plunger 26 as it isvthus movedrocking;the;lever .3l :in a'counterclockwise direction and: thereby moving the end of lthe.arm"33-upwar dly jlllltil 'ij',

is brought'to a Lstopby theengagement,oflthe arm with the fixed part lilo-of the 'vehicle The lever: 3| as itis thus being rocked,*rai ses the; member: .52 and thereby the .spring'yseat v53 and springx 55 until-the upper endofthe spring engages the spring seat54;.:x' 1he continued'movejment of the lever causesthe; spring '55 to; exert a considerably gupwardlyw directed forcevomgthe member 34 causing :the member to moveupwardly. Since the upper end of the membergtt isvrin 1 engagement ,with thevalve seat; tmember,-:39, up-

ward'movement :;will, be "imparted to the. valve seat member. :The valve seat-member first seats .upon the exhaust valve-4 9Vto1cl0sethejloadbrake cylinder exhaustcommunication' between the-diatpressure flows from the supply valve chamber 59 and thereby from the auxiliary reservoir to the load brake cylinderxdevicefi bywayof chamber 41, passages 48 and flfstrainer '45 and pipe 43.

Fluid'under pressure thusisupplied to the load brake cylinder device causes'zthe piston, piston rodand latch box mechanism associated with the piston rod to'move outwardlyiuntil the latch box "mechanism Operatesinto flocking engagement with thepush rod l2; The pistonof the load brake cylinder-device acts together withlthe empty brake cylinder piston to increase the braking force of thegbrake' rigging. 1 I

It will here be noted thatcthe'igreaterithe-distance the arm is'spaced'i'fro'm theifixed part I80 of the vehicle theJhigh'er the supply valve will be lifted from its'seat BI and the higher the exhaust valve will be-raised; 1 mi 1 i 1 Now as the brake cylinderIpressure in chamber 43 and acting on the upward flexed'diaphragm 40 of the load brakecontrolling ldevicegLtithe diaphragm and associated valve seat member *39 and member 34 will be forced downwardly against the opposing force of'the'springi55 carried'by the spring seat 53 which is maintained against downward movement. at this time by the piston iii-which is subjected to the pressure of fluid in chamber 2!, which pressure is increasing with the load brake cylinderpressure. As the'valve seat thus moves downwardlmthe spring 65 acts to move the supply. and exhaust valves '58'an'd 49, respectivelmstrut' 5G and spring 51 downwardly. The supply valve whe'nlit 'eng'ages'its seat 6| will cut off the supply of fluid under pressure to the load brake cylinder device 6, and since no further increase in loadbrake cylinder pressure is possible, the downward movement 'of the flexible diaphragm 40; valve seat member 39 and member 34 will cease and the exhaust valve 49 will be maintained seated on the valve seat member and thereby maintain the load brake cylinder exhaust communication closed. Thus thegload brake cylinder pressure is limited according to the weight of the load carried by the .vehicle body while-thqpressure of the empty brake cylindernt u se e ri e .3 0 th .fu r e rse sail d o b the: ra io f: th t p valve-der e- It will be understood that the greatenthe weight of the load on the vehicle the gre'ater .will -be the distance the supply valve must be moved-downwardly-to its seated position,. consequently; the; greater will the pressure of the-load brake linde -cha s to bewtd m eesthe 11 o: permit the valve to seat, thus the braking gr w is tz t cle-:21

..forceof-- he; valves will be p opqrtiqna to the Q Riazdseof ZPQ- OQd'bTakeQappli ati 'Whernin 'orderto'" release the brakes th brake pipe pressure has been increased and the triple valve, responseft'o 7 this increase, has assumed its release position; fluid'un'der pressure is vented r m. t e emp b ak nder; d &9 t atmosphere by way of pipe B transfer valve 'mech ism ,;p s ee-ie d lsxhe t mmunication; established by the vehicle valve 7 device.

A th .sam ti efl w er es r nted from the piston chamber 2 I andconn ected supply I valve chamber of the load brake controlling device by way-of strainerZZ- pipe S, past the open valve 3f ofthe transfer valve; mechanism 3, pas sage 3e and the triple valve exhaustcommunica tion.v When the pressure offluid Tin valve r c s, e; t he-flow fiflvid mm to theiamosphere as just .descrilpeti to av value slightly less than that of the :load brakefcylinder pressure :acting onthe underside of ithe supply .valve58, fluid at the load brake cylinder pressure p .raises the; valve from its. seat '6 I against the opposin vpressure of the light spring .64 Fluid under pressure now flows; fromthe loadbrake cylinder d evice 6- to the atmosphere-by way, of ifil trei er='a4 ;1? s -a d c am r d. cheg be =ha 4 a a e-. 9

strainer 22, pipe}, pasta-the open valve 3f-of the transfer valve 7 mechanism} and the triple valve exhaust communicatiom; It should be noted that fluid under pressure flows-irom both of the brake cylinderdevices by wayof the triple valve exhaust m icat -v NOW w e the e y a le brake cyli d ressuresheveb e r du ed o fl 4 teen pounds, the valve3fof the transfer valve de:

vice is automaticallyv closed by means of the spring 30, but the flow of fluid fromthefchamber il}of the load brake; cylinder device will continue; by

' way-of the passage 3h,whichby;pas ses the'valve tothe passage 36 and triple .valve exhaust com :munication, which passage fih; as; hereinbefore described is provided witha check valve 3i' which is adapted to prevent flow throughthe passage to, the pipe 9 andchamber 5 I; when an applica tion of the brakes is being'efiected, I .When the fluid pressure isvented from the chamber 2!, the spring acts to rock the lever 3| in a clockwise direction. ,flhisaction of the lever together with the actionfof the compressed spring 12! shifts the plunger 26; spring 3|! and piston 20 upwardly" to their normal release positions as shown-r. v.

When the spring 55 consequence, the member moves downwardly to its: normal position as shown,- permitting the exhaust valve 40 to move to. its normal supported position on the stopshoulder 50,,and also per! mitting the valve'seatpmember 39 ta move out-of engagement with :the; exhaust. valve-n, With the I exhaust :valve fin this 'position,'rthe loadbrake hasex andedm a ile height there will no longerbe any. upwardly diy rected force. acting on-the;-membe'r, 34'; and as a assaozo scylindenidevice: is; connected to; the: atmosphere :sorthat: ifija-ny' .air should-be: trapped: in thebrake cylinden' it williynow fiow to the. atmosphere; by

contained therein, will cause the devices to move tov their release: positions, the latch box mechannism during. the release: movement of the load brakevcylinder. pistonrod-being moved to its' push rodureleasingj position thus permitting the, free movement of the brake riggingzparts to; their brake releasing position as 155 rwelli known.

Preventing oscillations; tween the sprung and unsprtmg parts of tlteoehz'cl from; varying the adaustment of the loaded bmlc'e' controlling 1 device 7 i During: an application ofthe brakes, thearm 33w of thef loadbrake controlling device I will remain. in contactlwith'the fixed parti I of the vehicle, so that usualfunpreventable oscillations between :the sprung'and; unsprung parts oi: the

vehiclecause the lever 3!; to "be rocked'in one direction or. theg tother. Theseoscillations: are; of course very rapid; and whilethe 'operationaof the lever 31 in responsethereto does; tend to change the adjustment ofthe member; such-adjust ment issuccessfully resisted by the dash-pot ac"- tion- Off the, piston 35; acting in.,the oil contained inL-the: recess ordash-pdhfifi: p i

When th gbrakeszarereleased theend oft-the arm 33 willr be. spaced away from'vthe fixedpar-t .!:0,of the vehiele-so that oscillations between the sprung; and unsprung parts of the vehicle will not cause-operationof the. arm and associated movable parts; 015 the. load, controlling device; 1 thus relieving" these movable parts of, undue wear. v

I Glenemitrddnsidrations' I While the invention has been describedin con;- n'e'ction witnan automatic fluid pressurev brake equipment -in which there is employed a triple valve device it will be understood. that" itmay be employedtequally aswell in straight. air brake equipment or in other types of brake equipments. It will be understood thatjwhile the invention has been described as anjempty and load brake equipment itvma'y also-be termeda variable load brake equipment since the load, brake cylinder pressure maybe varied according to variationsin the weight of thel'oa'dicarried on. the vehicle. If desired'the conditioning of the loadbrake control" apparatus may' 'mo di'fy v by providingthe casing with?) stop which the upper face'of the supply 'va1ve itmay engage as soon as it is moved far enough trom its seat to provide the proper rate of 'flow offlu'id to the load brake cylinder devic 6', so that the conditioning movement of the lever 3|" will compress the spring and thereby increase its upwardly directed force on the member 34. As soon as fluid in chamber 43 at load brake cylinder pressure becomes sufiicient to overcome this spring force the diaphragm 40 will operate to move the member 34 a sufiicient distance to permit th supply valve to seat and, with the valve seated, the exhaust valve 9 will remain in engagement with the valve seat member 39 thereby maintaining the load brake cylinder device cut off from the atmosphere. In releasing the brakes the spring 55 will act to move the lever 3| and associated parts-to release position and will permit the member 34 to move downwardly to its normal release position in which thervalverzseatgmember 39;will,b,e: drawn out of seating engagementwith the exhaust valve 49.;

. While. one illustrativeembo'dimentyof the i cylinder to efiect anapplication of the brakes-,a 1

second brake cylinder device an'dmeans controlled according to the weighte zof the load on the vehicle for admitting fluid -under pressure, to said second brake cylinder devi-ceto eiiect; an increasein the degree of application-of theibrakes and for then-t cutting off thefiow-of fluid tosaid secondybrake cylinder device to a limit the? increase inthe degree of application of the brakes,-the flow of fluid *to said second brake cylinder device being independent of the operation of the first mentioned brake cylinder device; V r- 2. The combinationcwithuthe fluid, pressure brake equipment comprising; a brake cylinder, means forwsupplying fluid under;:pressurezto the brake cylinder toqefiect [an application ;of, the brakes, of: asecond; brake cylinder device; and means: operative, to, admit; fluid under pressure to" said second; brake cylinder device and operative accordingitoithe weightyof the load of" the vehicle for cutting off-l the flow ofafiuide under 7 oylinder to; efiect; an; application of thefbrakes,

of aa' secondbrake cylinder device; and; -mea ns operative according to.,th'e weight a of the-load on the vehicle togadmit fluidunder pressure to said second brake cylinder device and' operative according to the weight, of the load on the vehiele 'for cutting on the, flow off fluid to said second brake cylinder device, and thereby limiting the braking. power-thereof, the-flown of fiuidlto said second brake cylinder device being. independent of th 'operationl of.,the firstv mentioned brake cylinder'devicel,

r t.v In a fluid pressure bralie eduipment, in bullbination, anempty brake cylinder, device for pro.-

viding' brakingpower on alightly loaded vehicle and a load brake] cylinder device adapted; to] be cut intojoperation to. provide'increased braking power "on the vehicle." whe the} vehicle 7 is more heavily loaded; said vehicle" having an unsprung or relatively fixed part,.loa;1 brake cylinder control apparatus movable vertically relativ to the unsprung part of the vehicle different distances, depending upon differences in the weightof the a load carried by the vehicle and being adjustable to admit fluid under pressure to the load brake cylinder device and to limit the amount of fluid under pressure admitted to th load brake cylinder device, said control apparatus comprising adjusting means movable into abutting engagement with the unsprung part of the vehicle for determining the adjustment of the control apparatus, and means for actuating the adjusting means.

5. In a fluid pressure brake equipment, in combination, an empty brake cylinder device for providing braking power on a lightlyloaded vehicle and a load brake cylinder device adapted to be cut into operation to provide increased braking I power 'on the vehicle when the-vehicle'is more heavily loaded, said vehicle having an unsprung or relatively-fixed part, load brake cylinder control apparatus movable vertically relative to the 'movable' to first unseat said valve and to then engage an unsprung part of the vehicle to condition the apparatus for operation to limit; the amount of fluid under pressure admitted to'the load brake cylinder device, and" fluid pressure responsive means operative upon th initiation of a brake application for moving the valve conv trolling means intc engagementmwith the unsprung part of the vehicle; 1 1

6. In a fluid pressure brake equipment, in combination, an empty brake-cylinder device for providlng braking power on a lightly loaded vehicle and a load brake cylinder device adapted to be cut into operation'to provide increased braking power on the vehicle when the vehicle is more heavily loaded, said vehicle having an unsprung or relatively fixed part, load brake cylinder control apparatus movable vertically relative to the unsprung part ofthe vehicle different distances depending upon differences of weight of the load carried by the vehicle and r being adjustable to admitfluid under pressure to the load brake cylinder device and to limit th'eJamountof fluid under pressureadmitted to the load brake cylinder device, said load brake control apparatus comprising adjusting means movable a distance proportional to the degree of relative movement between the apparatus and fixed partof the 'vehicle to adjust the apparatus for'operation to limit the load brake cylinder pressure, and means operative-by fluid under pressure supplied to the load brake control apparatus in effecting an application, of the "brakes for actuating said adjusting means. U I

'7. In a fluid pressure brake equipment,in combination, an empty brake cylinder device for providing braking powe'r' on a lightly loaded vehicle and a load brakecylinder device adaptedto be cut into operation to provide increased braking 1 power 'on the vehicle when the vehicle'is more heavily loaded said vehicle having an unsprung or relatively fixed part, load brake cylinder con- =tro1' apparatus movablevertically relative "to the 'u'nsprung part'of the vehlcle' diflerent distances depending upon differences in the weight ofthe load carried by the vehicle andnbe'ing adjustable to admitfluid'underpressure to the load b'rake cylinder device and to limit the amount oil-fluid under: pressure admitted tothe load brake cyb :ind'er device, said control apparatus comprising adjustingmeans movable into abutting engagement with the unsprung part of the vehicle for de'ternu'niri'g the adjustment of theicontrol ap- V par'atus, i'means for v actuating the adjusting meansfand means for stabilizing said apparatus against accidental movement due to service shocks which may be transmitted thereto through V i the medium of the adjusting meanswhen the adjusting means is in enga emePiwn l flif iallnsprung part of the vehicle.

8. In a brake equipment in combination,

means for providing braking power on a lightly loaded vehicle and means adapted to be cutinto operation to provide increased-braking powerpn the vehicle when thevehicle is" more heavily loaded,'means governed by the weightoi'the on the vehicle for limiting 'the braking"power-10f the second mentioned means; and'm'eans operativ -independently of the operation of the -first mentioned means upon a'predetermined increase in the braking power of the first mentioned-means for cutting the last mentioned meansintoaction. i 9.111 a brakeequipmentg in combination, means for providing braking power onlalig'htl'y loaded vehicle and; meansadapte'd to bebutii to v operation to provide increased-braking p wer'on the vehicle when-the vehicleis' moreh'eavily loaded, means governed by-the weight a: th'-loa'do'n the-vehicle for cuttingthe secon'd' -mention d means into ia'ction and for limiting the braki'nfi power "of" the second mentionedmeans," and means operative independently for the operation of the first menticned means upon apredetermined increase in the braking powerizoi thefflrst mentioned means for cutting'the last mentioned to be cut into operation to "provide increased,

meansintolactio'n. V v v 10. In a fluid pressure brake equipment, in combination, an empty ibrake cylinder devic'eior providing braking power on a lightly loadedve hicle and a load brake, cylinder'ldevice adapted braking power on the vehicle when the vehicle is more heavily loaded, means governedfby the weightof the load on the vehicle for cuttingQsaid load brake cylinder device into action and; for

limiting the braking power of the load brake cylinder device, and means operative' -independ ently of the operation of jthelempty'bralreQcyl-im der device upon an increase in empty brake cylinder pressure for cutting said meansdrjito action; 7 l h r t Y. s JOSEPH '.1 

